US2928414A - Constant flow control device - Google Patents

Description

March 15, 1960 v. STREETER 2,923,414

CONSTANT FLOW CONTROL DEVICE Filed Jan. 17, 1955 2 Sheets-Sheet 1 FIG-.2 \i

INVENTOR VICTOR L. .JTREETER FIG. 1 57' a "W ATTORNEY5 March 15, 1960 V. L. STREETER CONSTANT FLOW CONTROL DEVICE Filed-Jan. 17, 1955 2 Sheets-Sheet 2 FIG. 5

by 5% Z'v/r INVENTOR ATTORNEYS CONSTANT FLOW CONTROL DEVICE Victor L. Streeter, Ann Arbor, Mich., assignor to The Dole Valve Company, Chicago, 111., a corporation of Illinois Application January 17, 1955, Serial No. 482,158 1 Claim. (Cl. 137-517 The present invention relates to a constant flow control device, and more particularly relates to a flow control device wherein the mechanism is operable to maintain the flow substantially constant substantially independently of pressure variations at the fluid inlet to the device and fluid pressure across the device.

The flow control device of the instant invention has many of the operating characteristics of the devices disclosed in my copending applications for'patent, such as my parent application entitled Adjustable Flow Control, US. Serial No. 446,867, filed July 30, 1954, of which this is a continuation-in-part, and my application for patent entitled Adjustable Flow Control, U.S. Serial No. 482,157, filed on even date herewith.

While the instant invention incorporates many of the principles and laws developed and set forth in those copending applications for patent, the present invention further has as one of its objects and principles the provision of a flow control device of the stated character which is preset and may be installed in a permanent installation without need for variation of the flow therethrough even though the device is finely adjustable. Devices embodying the principles of the present invention incorporate therein valve structure of the metering pin and orifice type wherein the orifice plate is fixed in its position while the metering pin is mounted on resilient springs and is contoured with the springs in contour cooperating to maintain flow through the device, substantially constant and independent of fluid pressure and fluid pressure drop variations.

It is, therefore, an important object of the present in-, vention to provide a new and improved constant flow control device of the metering pin and orifice type wherein the orifice plate is fixed in its position and the poppet or metering pin is contoured and mounted on non-linear springs which so cooperate with the contour of the poppet that flow through the device is substantially constant and substantially independent of fluid pressure and fluid pres,- sure drop variations across the device.

Still another object of the present invention is to provide a new and improved flow control for constant flow and wherein the orifice plate is fixed while the contoured poppet is resiliently mounted and wherein fiow through the device follows the law where C is the discharge coefficient.

It is still another object of the present invention to provide a new and improved control device a described wherein the metering pin has a profile which follows the law Still another object of the present invention is to provide a new and improved flow control device as described wherein the profile poppet or metering pin is supported by springs for resilient deflection with backing profile in accordance with the law l 9 i I}; a 1 31nd a) 4]+ (3 wherein i a F01 5: and 37:

+3EI Y Z Y F is the spring loading corresponding to head h Y is the displacement of the poppet as the fluid head changes from minimum design head to maximum design head.

Still other objects, features and advantages of the pressent invention will become readily apparent from the following detail description of the principles and an embodiment thereof, from the claims, and from the accompanying drawings, in which each and every detailshown is fully and completely disclosed as a part of this specification, and wherein like reference numerals refer to like parts and: Figure 1 is a vertical sectional view ofa constant flow control device embodying the principlesof the present invention and shown substantially as taken along the line II of Fig. 2; i

matic illustration of the backing plate and a single leaf 7 of the spring for supporting the contoured poppet; and

taining fluid flow rate substantially constant, quantitywise, and to maintain this flow constant substantially independent of pressure variations in the fluid flow lines.

In numerous of these installations it is in no way essen;

tial that the-flow control device be variable, except pos sibly for the purposes of slight adjustrnent 'of the device to the preselected flow levels.

In accordance with these needs, the present invention is provided to obviate the same and supply such a control device asthat illustrated in Figs. 1 and 2.

As illustrated in these two figures a flow control device 10 wherein the housing 11 is formed of an inlet section 12 and an outlet section 13 which are clamped and sealed together by means of bolts or screws 14 or the like which extend through flanges 15 and 16 on the mating faces thereof and radially outwardly thereof. The inlet section 12 also'has incorporated therein a' boss 17 which forms an inlet to the valve mechanism 18 within the confines of the housing, while the outlet section 13 has,

outlet '19 is controlled and maintained substantially constant through the operation of thevvalve device 18 within the housingll. The details of this flow controller follow the laws established in my aforementioned copending applications including my parent application and the identi- While variations may be made it ispreferred construcfied application filed on even date herewith. In the device tion that the tips 26 of the cantilever leaf springs 24 reof the instant invention, however, there is provided an main unsecured to the flanges or shoulders 27 and 28 so .orifice plate 20 (Fig. 1) which has a knife edge'orifice 21 that the springs may operate in a truly cantilever leaf position on the poppet head, In accordance with the of the metering pin head is therein and which is supported by two sections ofthejhous- 5 manner for deflection in a manneras shown in Fig. 3.

ing bybeingclamped betweenthe flanges 1 5 and '16 and Deflection of the cantilever leaf springs 24 is in a preby the screws or bolts 14. Thus,- the orifice plate-20 -is designed non-linear manner since these leaf springs are positively fixed and secured in place within the housing supported on a contoured segmented backing ring or plate 11 and provides a partition within the device and between 29 having a'contoured face 30 against which the springs the inlet 17 and the outlet 19 to stop fluid flow therebewill progressively lay down as described hereinafter and tween except through the knife edge orifice 21 (Fig.1). which may be cut away except under the spring leaves.

There is mounted for reciprocation within the orificell The backing plate 29 is supported on threaded studs and coaxially therewith, a profiled'or contoured metering 7 31-31 which are threaded through threaded apertures pin'or poppet 22 which has a contoured head 23 for co-' 32 (Fig.d) 'in 'the' orifice plate 20 and which are prooperation with the orifice 21 to limit fluid flow through vided with'nuts'33 'on"whichithe plate 29 rests. The studs the device to flow through the area between theedge of e 31 extend through the appropriate apertures 34,35 and the orifice 21 and the closest adjacent position on the 36, respectively, in the backing plate 29, the spring ring poppet head 23, note in this connection the illustratio'niof 25 and a clamping ring 37 so that the assembly is clamped Fig. 4 wherein the area here under 'di'scussion'is defined between the head 3801: the studs 31 and the nut 33 on each by revolution of the line S between the edge of the orifice stud.

and the closest adjacent position on the poppet head. The manner in which the spring will deflect due to ,r. This area is defined, in accordance with the theory of pressure variation across the poppet head is indicated in 3 Pappus, as. Fig. 3 wherein it is shown that the springs 24 lay down t progressively for continuous shortening thereof as the 'A-'-21r(r /(xw) +t force or pressure increases, againstthe contoured face e a of the backin'g plate 29. As developed in my aforewherein the letter designations represent the dimensioned mentioned copending applications, the relation between deslgnatlons 011 4' Where "0 is the diameter of the the backing and the spring with a poppet head as described fice, tis the'horizontal projection of the dimension s,"x" above should be is the distance from the beginning of the contour of the 30 poppet to the plane surface of the orifice, while x isthe distance from-the beginning of the contour to the control.

51"." d ltj --l n .g- 1 F013 'i 35 35 111 H (Z 3EIY principles of the present invention, however, Ais equal bevelopment of this law for the spring and the backing to 35 profile with respect to the metering pin or poppet profile H breaks down to min zY wherein H is'a fixed ratio of maximum head to minimum head within the design control range of the device and Y 40 is the dimension of maximum movement'for the poppet head. A is the annular area for poppet position ing the laws set forth hereinabO it will be that V V the flowthroughthe controller will be maintained sub- Equating these expressions and acting upon the same stantially constant and substantially independent of. presin the manner set out in my copending application filedo'n sure. jfhe device of the instant invention, however, may

F Ea-t go-n s In (1-2) -4]+ 3-e thespring, spring'backing and poppet profile obeyevendate'herewith it will be observed that be finely adjusted forpresetting atany desired flow con- "Y trol level within the design rangeof the device by ad- :c-w=,-(lt- /l'( justi'nent of .the screws or studs 31 which will vary the.

In Y :position of the poppet head within the orifice and thereand it further develops therefrom that the proper profile by reset or adjust the flow level of the device. It will be t understood, of course, thatthis is primarily a fine adjust- 111 mi-i If be understood of" course, that 'thg expression at Of operation fOl' the mm H device, which level is a designed level. It will also be A 757 understood that numerous variat ons and modifications r r 5 may be made without departing from the true spirit and s the basic law for the pin profile when solved. for as scope of thencvel'concepts andprinciplesof-myjinvention t and IS developed in both of myffdr'ementioned applicaandIgtherefore'inte nd to cover those modifications and i trons. 1 j U variations.

' In order that the poppet head cooperate properly with I claim as my in'vention;

the fixed orifice, howeverfit is supported on laplurality 5 a 'In a flow control dvice'to maintain the flow rate of of cantilever type leaf springs 24-24'which radiateim fluid in a fluid.system substantially constant, a housing wardly from a ring 25 with which they are integral. The forfiuid flow therethrough, an orifice plate mounted in tip ends"26+26 of the leaf'springs 24 support the'po'ppet saidho'usingin the path offlow therethrough and secured orfin' tering pin 22 by extending between a pair of radial theret'q said platehaying a substantially knife edge ant 1 annular shoulders 27 and 28 in the upper uncountered 7 nular orifice therein, a contoured poppet having a profile regionof the metering pm. r law f 5 wherein x is the distance from the beginning of the contour to the control position of the poppet head Y is the dimension of maximum movement for the popper head In is the natural logarithm H is the fixed ratio of maximum head to minimum head within the design control range r is the diameter of the orifice t is the horizontal projection of a line from the edge of the orifice to the closed adjacent position on the poppet head A is the flow area for a poppet position when the plane surface of the orifice coincides with the beginning of the curvature of the poppet and wherein is dimensionless axial coordinate of backing plate x is dimensionless radial coordinate of backing plate In is the natural logarithm H is ratio of maximum fluid head to minimum fluid head I is spring length G is the spring characteristic= 3E1 Y References Cited in the file of this patent UNITED STATES PATENTS 1,154,962 Bayles Sept. 28, 1915 1,658,547 Aseltine Feb. 7, 1928 1,944,088 Linderoth Jan. 16, 1934 2,179,144 Buttner Nov. 7, 1939 2,295,044 McCarty Sept. 8, 1942 2,684,081 Chace July 20, 1954 2,827,076 Obermaier Mar. 18, 1958 I FOREIGN PATENTS 595,243 Germany Apr. 5, 1934 OTHER REFERENCES A.S.M.E. Transactions (Clurman), vol. 73, published by A.S.M.E., 1951, pp. -1 61 (copy in Scientific Library).

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